- This article is about telecommunications. For the early computer programming language see, see Short Code (Computer language).
Short codes, also known short numbers or Common Short Codes (CSC) are special telephone numbers, significantly shorter than full telephone numbers, which can be used to address SMS and MMS messages from mobile telephones. They are designed to be shorter to read out and easier to remember than a normal length telephone number. While similar to telephone numbers, they are, at the technological level, unique to each operator, although providers generally have agreements to avoid overlaps.
Short codes are widely used for value-added services such as television voting, ordering ringtones, charity donations and mobile services (such as Google's SMS search service). Messages sent to short code numbers are generally billed at a higher rate than a standard SMS.
Regional differences
Codes are 5 or 6 digits in length. Codes starting with 4 are not permitted due to handset incompatibilities.
Codes are 4 digits in length.
Codes are 5 digits in length, starting with 6 or 8 (codes starting in 5 and 7 exist, but are reserved for future expansion). Individual network operators may come to an agreement with customers, allowing any number to be used - except for adult content services, which must use codes starting with 69 or 89.
As of May 31 2006 the standard lengths for interoperable Short Codes are 5 and 6 digits. Carriers use short codes with fewer digits for carrier specific programs - e.g., text 611 to see how many minutes you have remaining on your plan. Codes starting with 1 are not permitted.
Messages sent to/from these short codes are known as Premium Rate SMS. Codes are 7 digits in length for MO and 5 (not billed) or 8 (billed) for MT direction, starting with 9, while two or three (depending on billing type=MO/MT) trailing digits express the price, e.g. sms sent to 9090930 is billed for 30 CZK. Leading 3 digits are purpose type prefixes (908=micropayments, 909=adult content, 900=all other), digits at position 4 and 5 determinates the service provider registered by a network operator. There are also other 4digit shortcodes, used by a network operators for service only purposes (operator dependent)
Short Codes are generally 8 digits in length and start with 19xx-xxxx and are commonly referred to as Premium Rate SMS Messages.